This invention relates to a process for the production of pourable free-flowing granules of useful materials or mixtures thereof, which are suitable as and/or for use in wetting agents, detergents and/or cleaning products, from aqueous solutions and/or suspensions of such materials by fluidized-bed spray granulation in a hot fluidizing gas in the region of normal pressure.
Processes for the production of particles on an industrial scale from initially liquid products, i.e. from solutions or suspensions, include in particular spray drying, spray drying with integrated fluidized-bed agglomeration and fluidized-bed spray granulation. For decades now, spray drying has been typically used worldwide for the industrial-scale production of granules from aqueous preparations of useful materials of the type mentioned at the beginning. Hot air or mixtures of air and hot waste combustion gases are used as the drying gas stream. Washing powders and useful materials and mixtures thereof for the production of laundry detergents in pourable free-flowing powder form are industrially obtained in so-called spray-drying towers generally operated at ambient pressure either in countercurrent or, occasionally, in co-current.